This invention generally relates to a method and apparatus that can be employed for ultrasonic processing operations. In particular features, the method and apparatus can include a rotary ultrasonic horn, and the ultrasonic processing can include an ultrasonic bonding operation. More particularly, the invention relates to an ultrasonic processing method and apparatus which can provide for an operative isolation of the rotary horn while employing a connection system that has relatively high rigidity and stiffness.
Conventional ultrasonic systems have included a rotary horn which cooperates with a rotary anvil. The conventional rotary ultrasonic horns have been supported and mounted by employing rubber or other elastomeric components to provide ultrasonic isolation. As a result, the ultrasonic horn has exhibited low static stiffness, low dynamic stiffness, and has exhibited excessively large amounts of run-out or other displacements during ordinary operation. Additionally, the conventional ultrasonic horn systems have employed complicated and unreliable torque transmission techniques.
To help address the various shortcomings, the conventional ultrasonic bonding systems have employed additional support wheels to help maintain the ultrasonic horn in a desired position relative to the cooperating rotary anvil. Typically, the support wheels have been configured to hold the rotary horn in a substantially continuous, direct contact with the rotary anvil during ordinary operation. The use of such support wheels, however, has excessively increased the audible noise from the system, and has caused excessive wear on the working surface of the ultrasonic horn. Additionally, the horn has exhibited uneven wear, or has required the use of an oscillation mechanism to more evenly distribute the wear. Torque transmission systems needed for driving the rotary horn have been excessively costly, have required excessive maintenance, and have been difficult to setup and adjust. The conventional ultrasonic horn systems have also created areas on the working surface of the horn that have been unsuitable for performing desired bonding operations, and have not provided sufficient levels of dynamic stability. Additionally, the conventional ultrasonic bonding systems have required excessively critical adjustments, and have exhibited excessive complexity and excessive costs. Where rubber or other elastic materials are employed to provide acoustic isolation mounts, the mounts can generate excessive reflected energy if the elastomeric material is over compressed. As a result, there has been a continued need for improved ultrasonic bonding systems.
An ultrasonic processing method and apparatus can include a rotatable ultrasonic horn member operatively joined to an isolation member. In a particular aspect, the isolation member can exhibit high rigidity. In a further feature, the isolation member can be configured to operatively bend under a horn-life range of sonic frequencies to provide an operative component of motion along a radial direction and an operative component of motion along an axial direction.
In a particular aspect, the isolation member can have a radial isolation component and an axial isolation component. The radial isolation component can be operatively joined to the axle member, and can be configured to extend at least radially from the axle member. The radial isolation component can be configured to operatively bend under the horn-life range of sonic frequencies. The axial isolation component can be operatively joined to an operative portion of the radial isolation component, and can be configured to extend at least axially from the radial isolation component. The axial isolation component can be configured to operatively bend under the horn-life range of sonic frequencies.
The various aspects, features and configurations of the method and apparatus of the invention can provide a distinctive, rotary ultrasonic horn system which includes a corresponding wave-guide and at least one isolation member that has high rigidity and stiffness. The isolation member can operably isolate the radial motion that can arise at the longitudinal node of a wave-guide, and can provide sufficient bandwidth to compensate for nodal shifts that can occur during ordinary operation. The isolation member can also provide improved stiffness to reduce deflections under load. The increased stiffness can help maintain concentricity, and help to reduce run-out displacements. Additionally, the isolation member can more efficiently transmit torque and can provide improved effectiveness and efficiency. The isolation member can also be configured to reduce stress concentrations and to increase fatigue resistance, and can provide for a mounting system that can reduce relative motions between component parts. The method and apparatus of the invention can reduce the need for elastomeric isolation components, and can eliminate the need for conventional elastomeric O-rings and associated isolation-ring hardware. The method and apparatus can also reduce the need for torque transmission keys, and can avoid the use of auxiliary support wheels for maintaining the desired locations of the rotary horn and rotary anvil.